whats better J or X heads

Just a quick pic on how not to do it when your installing larger valves, this is a set of ‘73 340 587 heads I’m helping a friend go through.2.02/1.60 installation and new guides. The intake not being blended isn’t as bad as the exhaust, being the charge mixture will tend to jump, but there are still turbulent losses. Leaving the exhaust like this would be disastrous, though. hardened seat installation left a huge step over to the bowl and is going to have to be blended back in. Valves weren’t back cut either, and the valve job is getting a closer look (re-done on a serdi type machine with bowl and chamber cuts) too. It was destined for pure stock oval track use but it looked like they started running out of money after they got so far into the heads. The bottom end is a work of art, though.